Pediatric constipation, frequently (70%) accompanied by encopresis, is estimated to effect 4-8% of children. Besides leading to infrequent and painful bowel movements, it may result in bowel habit disruptions, family stress, peer rejection, academic disruptions, and impaired psychosocial development. While there is a great deal of speculation about the mechanisms of both constipation and its standard medical care, little systematic research exists. Standard medical care, which involves enema, laxative, and dietary modifications, is typically protracted (e.g., 6 months) and marginally effective (e.g., 30%). While variations of behavioral toilet training (regular toilet time, contingency management, relaxation training) have sometimes been employed, there are no systematic outcome studies. It is estimated that 50-80% of constipated children typically paradoxically tighten their external anal sphincter (EAS) when attempting defecation, and thereby produce a functional anal canal obstruction. Anal manometric biofeedback has been employed to train relaxation of the EAS when straining to defecate. This appears promising, but only two comparative outcome studies exist in the literature. Neither study was designed to identify the unique contribution of biofeedback separate from behavioral toilet training, and neither evaluated treatment effects on psychosocial or developmental issues. There are major barriers to routine use of such manometric biofeedback: It requires sophisticated and expensive equipment and staff, it is not generally available, its visual feedback display is poor due to large amounts of distracting and irrelevant information, and it is extremely physically and psychologically invasive to children. Our proposed research evaluates the short and long term relative efficacy of four treatment protocols: 1) standard medical care alone, and in combination with 2) behavioral toilet training, 3) a more available, simpler and less invasive electromyographic biofeedback and 4) toilet training plus biofeedback. The additive design will evaluate the relative cost-effectiveness of the three treatment components and will provide additional information about the mechanisms and consequences of pediatric constipation and encopresis.